1. The work done on an object does not depend upon Which of the following?
(b) force applied
(c) angle between force and displacement
(d) initial velocity of the object
2. In case of negative work, what is the angle between the force and displacement?
(a) 0 degree
(b) 45 degree
(c) 90 degree
(d) 180 degree
3. Which one of the following is not the unit of energy?
(b) newton metre
(d) kilowatt hour
4. When a body falls freely towards the earth, then its total energy-
(c) remains constant
(d) first increases and then decreases
At every point total energy remains constant.
5. A body is falling from a height h. After it has fallen a height h/2 , it will possess-
(a) only potential energy
(b) only kinetic energy
(c) half potential and half kinetic energy
(d) more kinetic and less potential energy
6. A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car-
(a) does not change
(b) becomes twice to that of initial
(c) becomes 4 times that of initial
(d) becomes 16 times that of initial
Potential energy depends on height and there is levelled road, no change in height. So Potential energy does not change.
7. A girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a levelled road. The work done against the gravitational force will be? (g =10 ms–2)
(a) 6 ×103 J
(b) 6 J
(c) 0.6 J
In this case the angle between force and displacement is “90˚ “.
W = FS cosθ
And Cos 90˚ = 0
So W = 0
8. Water stored in a dam possesses-
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
It possess only Potential energy.
9. Potential energy and kinetic energy are types of-
(a) Electrical energy
(b) Magnetic energy
(c) Thermal energy
(d) Mechanical energy
10. How are Joule (J) and ergs (erg) related?
(a) 1J = 10^7 erg
(b) 1erg = 10^-7J
(c) 1J = 10^-7 erg